Internal treatment of pipes



June 5, 1962 E. E. CUMMINGS 3,037,228

INTERNAL TREATMENT OF PIPES Filed March 20, 1961 3 SheetsSheet 1 E f. ("away/0y;

INVENTOR.

ATTO/P/Vfy June 5, 1962 E. E. CUMMINGS INTERNAL TREATMENT OF PIPES 5 Sheets-Sheet 2 E. E. CU/77/77/f79d' IN V EN TOR.

BY 2, c

Filed March 20, 1961 ATTOR/Vfy June 5, 1962 E. CUMMINGS 3,037,228

INTERNAL TREATMENT OF PIPES Filgd March 20, 1961 3 Sheets-Sheet 3 f. f. Camp /x79;

IN V EN TOR.

BY Q c we? Arrow/5r 3,037,228 Patented June 5, 1962 Texas Filed Mar. 20, 1961, Ser. No. 97,092 4 Claims. (Cl. 15-1041) This invention relates to an improved machine for the cleaning of mill scale, rust and other surface dirt from the interior of tubular goods and particularly fluid flow conduits made by bending steel plate into tube shape and welding together the adjacent longitudinal edges. The weld line usually presents an inward protuberance which tends to defeat thorough cleaning action by rotary brush procedures as heretofore practiced and the uncleaned surface precludes good adherence of paint applied to pipe interiors. When a pipe engaging brush is driven at high peripheral speeds, its bristles drag along on and scrape or abrade the cylindrical pipe surface but when they strike or bump against an internal seam ridge, the bristles flex back and bounce across the ridge and after passing beyond the rise they come back to the cylindrical pipe surface along lines circularly spaced beyond the seam without having contacted and effectively cleaned the area of recession in the corner between the far side of the ridge and the cylinder surfaces. Failure to get rid of dirt accumulations within the corner area breaks the continuity of brushing and later bonding reliability of an applied paint coating which in turn can defeat prolonged corrosion protection.

It is an object of the present invention to provide mechanism for more effective brush cleaning of the entire pipe interior surfaces, inclusive of corner regions on both sides of an internal bump or other surface irregula rity.

Another object is to provide for mounting a pair of brush assemblies to be run through a pipe on a longitudinally projecting boom and to be driven by a power transmitting connection for concurrent rotation of the two brushes in directions counter one to another for balancing torque forces, but more particularly for insuring that corner recesses on opposite sides of a seam will be worked by one or the other of the oppositely rotating brushes for obtaining uninterrupted cleaning of all the surface throughout the internal circumference of the pipe.

A further object of the invention is to provide an improved brush assembly structure which will be simple in design for low initial cost, with long life but with ease of assembly and disassembly for inspection and for replacement of wear and breakage.

A preferred embodiment of the invention is illustrated in the accompanying drawings wherein FIG. 1 is a side elevation of pipe working components at the forward end of the boom mounted for reciprocation into and out of the pipe; FIG. 2 is an elevation showing a boom continuation of the parts seen in FIG. 1; FIG. 3 is an en larged fragmentary view substantially on line 33 of FIG. 1; and FIGS. 4, and 6 are transverse sectional views on lines 44, 5-5 and 66 of FIG. 1.

The drawings show the improved internal pipe working mechanism which is to be mounted on and constitute the forward end of a boom or stinger projected from a motor driven reciprocatory carriage tracking on guide rails whereby the working mechanism under control of carriage travel is projected into and retracted from and in substantially coaxial relation with the inside of a pipe while the pipe is located in end to end longitudinal alignment with the tracking rails, all in a general arrangement similar to that of Cummings Patent 2,792,807, dated May 21, 1959.

In the present instance, the forwardly projecting and traveling carriage boom is an assembled framework 1 conveniently made up of longitudinal stringers and diagonal braces with a number of longitudinally spaced apart suspension wheels 2 on both sides of the boom to ride on a pair of transversely spaced and ground supported rails 3 and on the bottom inside pipe wall 4 in the back and forth working strokes of the machine. For adjustment to fit a range of different pipe diameters, the wheel 2 is mounted by a crank lever 5 dependent from a pivot connection with the frame 1 and about which the crank 5 can be swung or cranked to selected positions and then secured by a clamp nut whose stud is within an arcuate slot 6 in the lever.

Projected ahead of the forward end of the main frame 1 is a smaller frame extension or supplemental front nose assembly consisting essentially of a set of four circularly spaced apart angle iron straps which have rearward length portions fitted inside the adjoining main frame and stiffened thereby and secured in place by suitable transverse straps or plates such as shown at 8 in FIG. 2. FIGS. 4, 5 and 6 show these longitudinal angle straps 7 with their inner sides facing inwardly and in symmetrical disposition about the center line so that the side flanges of each strap are in the planes of adjoining flanges of adjacent straps and the several straps in combination provide the corners of a square or polygonal outline in transverse section. This arrangement facilitates the placement and removal of subassembly components by the sleeved fitment to the set of framing straps 7 of transverse mounting plates or rings having corresponding square openings therethrough.

Apair of side by side and counterrotating brush subassemblies surround the boom frame extension afforded by the ninety degree spaced apart angle straps 7. Each subassembly includes a pair of longitudinally spaced apart brush supporting plates or rings 9-9 having rotatable bearing on rollers 1010 carried by a pair of stationary mounting rings 11-11 and central square openings through the rings 11-11 fit the rectangle section of the angle strap frame. Accordingly, the brush subassemblies by reason of their respective sets of mounting rings, can be sleeved in succession on or oil? the frame at its forward end and can be suitably secured in operative positions as by set screws 12, shown in FIG. '6.

In forwardly spaced relation to the brush assemblies, another mounting ring 13 is similarly fitted to the square section frame and carries in subassembly relation a number of pipe engaging guide wheels and a pressure air nozzle arrangement for blowing sweepings out of the pipe. The air nozzles consist of a number of rearwardly and outwardly directed pipes 14 projecting from an arcuate manifold or curved pipe 15 located below the frame and bracketed to the back of the mounting ring 13. Radially adjustably bolted on the opposite face of the mounting ring 13 are two spaced sets of dependent straps 16 for mounting supporting rollers 17 for tracking on the pipe 4. A third roller 18 is carried by a swinging lever pivotally connected at the top of the mounting ring 15 and provided with a take-up spring 19 to bias the roller 18 outwardly.

Detachably bolted on the forward end of the boom frame extension is a shelf 20 for mounting a motor 21 driven at high speed, either electrically or by fluid pres sure, and whose hollow drive shaft is coaxial with the counterrotating brushes and carries a hollow paint spinner rotor 22 whose rim is perforated for centrifugal ejection of paint as a liquid spray projected radially outwardly to coat the pipe surface with a smooth corrosion resistant film. A paint deflector shield 23 is clamped by the motor supporting shelf 20 and serves as a baffle both to protect the paint spinning head from dust blown past the head and to deflect paint spray away from the brush assemblies and their drive trains.

Liquid paint is delivered to the spinner through its hollow motor drive shaft. Conduits for paint supply to the hollow drive shaft, for motor driving energy and for supply to the air nozzles, as well as wiring for solenoid control valves in the fluid flow conduits, may be led forwardly in a bundle through the central space within the boom frame. Such conduits are incidental and have not been illustrated, to eliminate unnecessary complication of the drawing. Another set of cleaning nozzles 24 on axes inclined outwardly and forwardly, project from an arcuate manifold pipe 25 which is supplied with controlled pressure air and is centrally mounted on the forward boom extension adjacent and behind the rearmost of the pair of counterrotating brush subassemblies.

The two brush subassemblies are structurally alike but are positioned in reverse end relation. In each instance, the longitudinally spaced apart mounting rings 11-11 are joined together near their outer edges by a set of three equally spaced apart spacer bolts 26. As seen in FIG. 3, each bolt 26 rotatably mounts a pair of peripherally grooved rollers longitudinally spaced apart, and riding within and retained by the peripheral grooves are the rotatable brush carrying rings 9 forming a part of the Wheel assembly. One of the paired rotary rings 9 has fixed thereto and laterally projected therefrom a circular succession of arms 27 connected with a chain sprocket wheel 28. In the case of the foremost brush subassembly, its sprocket wheel 28 is at the forward end and is to be driven in a counterclockwise direction, as viewed in FIG. 5, and in the case of the rearmost brush subassembly, its sprocket wheel 28 is at the rearward end and is to be driven in a clockwise direction, as viewed in FIG. 6.

For the transmission of power to the two subassemblies in opposite hands of rotation, there is shown in FIG. 2 a power divider gear box 29 having a pair of intermeshing gears each connected to a power output shaft. The power input shaft of the divider 29 receives drive from a power take-off gear from the usual carriage drive motor. One output shaft of the power divider 29 is connected through a universally joined propeller shaft 30 with a sprocket mounted in a frame bracketed bearing 31 and coupled by a chain with the clockwise rotating sprocket 28 of the rearmost brush unit and the other and oppositely rotating shaft of the power divider 29 is coupled through universally joined shaft 32 located within the central boom space and with a drive chain 33, a counter shaft supported in a frame bracket 34 and a drive chain 35 entrained on the sprocket 28 of the foremost brush unit for its counterclockwise rotation, as seen in FIG. 5.

Each pair of brush rotating rings 99 has a set of three equally spaced apart connecting bolts 36 joining the rims of the rings and extending in parallelism with the axis of wheel rotation. Centrally of each connecting bolt 36 is a spacer sleeve 37 having an outwardly projecting ear in which is screw threaded one end of a stud 38 surrounded by an adjustable compression coil spring 39 to exert an outward yieldable bias on the free end of a lever arm 40. This free end of the lever arm 40 is provided with a pivoted eye on which the movable outer end of the coil spring 39 bears and through which the outer end of the stud 38 is slidable. A terminal head on the stud is provided to engage with the eye and limit outward movement of the lever arm 40. From its free end connection with the stud 33, the lever arm 40 projects in the direction of forward rotation and follows a line of compound curvature so as to turn abruptly inwardly near its leading end. In the region adjacent its free or trailing end, the curvature of the lever arm is substantially concentric to pipe wall circularity and the lever width exceeds the space between the mounting rings 11-11. Mounted on the outer face of this trailing end are suitable wire bristle brushes 41 which are to scrape and brush loose any dirt on and clean the pipe wall surface. Ahead of the brush carrying and pipe concentric region, the forward end of the lever arm and for transferring to the lever arm the fornext connecting bolt 36 in the direction of forward rotation and is narrower than the space between the rotating rings 9-9. Also, its center area is relieved or removed to provide a pair of spaced apart legs which straddle the central spacer sleeve 3'7 on the adjacent connecting bolt 36. These legs terminate in hollow bosses or eyes to receive the bolt 36 for a pivotal mounting connection of the lever and for transferring to the lever arm the forwarded drive rotation of the rings 9-9. The pivotal swing in part will be responsive to centrifugal force along with the adjusted force of the coil spring 39 acting on the trailing end of the lever for maintaining proper Working contact of the brush bristles with the pipe and the scraping action on the pipe surface.

During the counterrotation of the brush carrying wheels in a pipe, the several brushes on each wheel approach surface irregularities, such as an inward weld ridge 42, from one side. That side of the protruding ridge facing the coming brush will first be swept by the tips of the flexible wire bristles and individual bristles will tend to deflect backwardly as their tips ride up and across the ridge. In the interval of successive bristle crossings, the free end of the pivoted brush dragging lever arm may be bumped inwardly and then rebound back against the pipe wall after the lever carried brushes clear the ridge. In any event, return of the bristle tips for scraping the far side of the ridge and into the far corner area does not dependably and effectively occur but with the counterrotating brushes as here disclosed, both ridge sides and corners will be swept and cleaned, one by the bristle tips of those brushes which rotate in one direction and the other by the bristles of the brushes rotating in the opposite direction.

In the use of the machine, the carriage mounted boom and its operating components are initially in retracted position to enable a previously worked pipe to be replaced by a new pipe in alignment with the trackway 3 and on supporting beams 43, as seen in FIG. 2. Suitable clamps, of which one is indicated generally by broken lines at 44 in FIG. 2, locate the pipe. The boom supporting carriage is to be driven forward with the two sets of brushes rotating as they enter the pipe and pass on to its opposite end. The rate of carriage travel in relation to the speed of brush rotation will be such that all pipe internal surface will be scrubbed by both brushes to insure dislodgment of dirt and brush contact with both sides of the weld seam. During forward passage, pressure air will be discharged at the forwardly directed nozzles 24 to blow cleanings forward beyond the brushes and out the front end of the pipe. Such cleanings are in the form of a fine dust and become entrained in the stream of pressure air and are blown out as a cloud having a velocity much in excess of the speed of boom travel. They will be blown out as fast as formed, without piling up or being left behind. Unless the pipe being operated on is unusually dirty, it can be cleaned in one forward stroke but as many strokes back and forth can be taken as needed. When the pipe surface is conditioned for a coating operation, the rotary brushes can be stopped or can be continued if desired but in any event, pressure air supply is now delivered from the rearwardly disposed nozzles 14 for getting rid of loose material, if any, on the back stroke and on the final back stroke the paint spinner wheel 22 is actuated for depositing a protective coating on the cleaned inside pipe surface.

The foregoing deals with only a single embodiment of the invention but it will be understood that such modifications and structural variants may be made as come within the scope of the appended claims.

What is claimed is:

1. In mechanism especially adapted for internal brush cleaning of a pipe having an inwardly protruding and longitudinally extending weld seam, a reciprocatory boom having a forward nose extension for entrance into and passage longitudinally through a pipe and a pair of counterrotatable brush assemblies carried in longitudinal succession by said nose extension and each comprised of a pair of longitudinally spaced apart mounting rings sleeved on said nose extension, two sets of circularly spaced guide rollers mounted by the rings adjacent the peripheries thereof and one set adjacent each mounting ring, a pair of longitudinally spaced apart rotatable rings having their inner circular edges fitted to the guide rollers of said sets respectively, circularly spaced apart pintle pins extending between and joining the rim portions of the rotatable rings, a drive connection for imparting rotation to said rotatable rings in a given direction, a circular succession of brush carrying arms, each pivotally sleeved at one end on a pintle pin and projected therefrom to its free end portion in a direction opposite to said given direction of rotation of the rotatable rings, brush means on the outer face of said free end portion of each arm, spring means acting on each arm in a direction biasing its free end portion outwardly and means to transmit drive to the drive connections of both assemblies and in directions one opposite to the other.

2. In apparatus especially adapted for internally working pipe surfaces having an inwardly protruding longitudinal seam, elongated boom means having a forward nose portion, pipe locating means for positioning pipe coaxially of the boom, means whereby longitudinal movement of one of said means enables pipe reception of said nose portion and a pair of counterrotatable brush assemblies mounted in longitudinal succession on said nose portion and each comprised of a rotatable ring, a drive connection therewith operable to rotate the ring in a given direction, a brush supporting lever having pivotal connection with the ring on an axis parallel with the rotational axis thereof and having a brush mounting portion spaced from its pivotal connection and rearwardly of the direction of forward rotation of the ring for a centrifugal outwardly biasing tendency at said brush mounting port-ion upon ring rotation and power transmitting means coupled to the drive connections of both assemblies to effect their counterdirectional rotation.

3. In apparatus adapted especially for internal working of a pipe surface having an inwardly protruding longitudinal seam, an elongated boom having a forward nose portion for reception and relative longitudinal travel within a pipe, a pair of brush assemblies rotatably mounted in longitudinal succession on said nose portion, means to rotate said brushes opposite to one another, each brush assembly including a rotatable wheel and a brush carrying lever having pivotal connection with the wheel on an axis parallel with the wheel axis of rotation and having an outwardly yieldably biased brush carrying portion in trailing relation to its pivotal connection.

4. In apparatus adapted especially for internal working of a pipe surface having an inwardly protruding longitudinal seam, an elongated boom having a forward extension of reduced transverse size and of a perimeter of polygonal outline in transverse section, a pair of mounting rings having central openings whose transverse outline and size correspond to and enable them to be sleeved axially on said forward extension in nonrotatable fit thereto, means detachably locating said rings on the forward extension against axial displacement from positions in axially spaced apart succession, rotatable rings having guide bearing support on the mounting rings, drive connections with the rotatable rings operating to turn said rings counter to one another and radially outwardly biased cleaning brushes carried by said rotatable rings for inward deflection upon striking a pipe seam, said counterrotating brushes :co-operating with one another to elfectively sweep the pipe wall surface in the corners of both sides of an inwardly protruding seam.

References Cited in the file of this patent UNITED STATES PATENTS 1,988,329 Perkins Ian. 15, 1935 2,128,822 Home Aug. 30, 1938 2,792,807 Cummings May 21, 1957 2,800,875 Jewell July 30, 1957 2,909,796 Ver Nooy Oct. 27, 1959 

